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/*

 *  NOTE: Each task has an interrupt semaphore associated with it.

 *        No matter which interrupt occurs that it has registered,

 *        the same semaphore is used.

 *

 *  This whole interrupt scheme may have been eliminated in a later draft.

 *

 *  $Id: intr.c,v 1.2 2001-09-27 11:59:17 chris Exp $

 */

#include <errno.h>

#include <intr.h>

#include <pthread.h>

#include <rtems/system.h>

#include <rtems/score/isr.h>

#include <rtems/score/coresem.h>

#include <rtems/score/thread.h>

#include <rtems/score/watchdog.h>

#include <rtems/posix/intr.h>

#include <rtems/posix/time.h>

#include <rtems/posix/threadsup.h>

/*

 *  _POSIX_Interrupt_Manager_initialization

 *

 *  DESCRIPTION:

 *

 *  This routine performs the initialization necessary for this manager.

 */

void _POSIX_Interrupt_Manager_initialization(

  unsigned32  maximum_interrupt_handlers

)

{

  unsigned32                index;

  POSIX_Interrupt_Control  *the_vector;

  _Objects_Initialize_information(

    &_POSIX_Interrupt_Handlers_Information,

    OBJECTS_POSIX_INTERRUPTS,

    FALSE,

    maximum_interrupt_handlers,

    sizeof( POSIX_Interrupt_Handler_control ),

    FALSE,

    0,

    FALSE

  );

  for ( index=0 ; index < CPU_INTERRUPT_NUMBER_OF_VECTORS ; index++ ) {

    the_vector = &_POSIX_Interrupt_Information[ index ];

    the_vector->number_installed = 0;

    the_vector->lock_count       = 0;

    the_vector->deferred_count   = 0;

    _Chain_Initialize_empty( &the_vector->Handlers );

  }

}

/*PAGE

 *

 *  22.3.1 Associate a User-Written ISR with an Interrupt, P1003.4b/D8, p. 74

 */

int intr_capture(

  intr_t          intr,

  int           (*intr_handler)( void *area ),

  volatile void   *area,

  size_t           areasize

)

{

  POSIX_Interrupt_Handler_control   *the_intr;

  POSIX_Interrupt_Control           *the_vector;

  POSIX_API_Thread_Support_Control  *thread_support;

  proc_ptr                           old_handler;

  if ( !_ISR_Is_vector_number_valid( intr ) ||

       !_ISR_Is_valid_user_handler( intr_handler ) )

    return EINVAL;

  _Thread_Disable_dispatch();

  the_intr = _POSIX_Interrupt_Allocate();

  if ( !the_intr ) {

    _Thread_Enable_dispatch();

    return ENOMEM;

  }

  the_vector = &_POSIX_Interrupt_Information[ intr ];

  the_intr->vector         = intr;

  the_intr->handler        = intr_handler;

  the_intr->user_data_area = area;

  the_intr->server         = _Thread_Executing;

  the_intr->is_active      = TRUE;

  thread_support = _Thread_Executing->API_Extensions[ THREAD_API_POSIX ];

  thread_support->interrupts_installed++;

/* XXX should we malloc the semaphore on the fly???  if so we probably need to

   release it when the thread has released all interrupts and keep

   a count of how many it has installed.  CURRENTLY NO.. ALLOCATED w/TCB

*/

  /*

   *  This is sufficient to have the handlers invoked in the opposite

   *  order of installation.  The loop invoking them can then go from

   *  the front of the list to the end.

   */

  _Chain_Prepend( &the_vector->Handlers, &the_intr->Object.Node );

  if ( !the_vector->number_installed++ )

    _ISR_Install_vector(

      intr,

      (proc_ptr) _POSIX_Interrupt_Handler,

      &old_handler

    );

  _Objects_Open( &_POSIX_Interrupt_Handlers_Information, &the_intr->Object, 0 );

  /*

   *  Normally, an Id would be returned here.

   */

  _Thread_Enable_dispatch();

  return 0;

}

/*PAGE

 *

 *  22.3.1 Associate a User-Written ISR with an Interrupt, P1003.4b/D8, p. 74

 */

int intr_release(

  intr_t    intr,

  int     (*intr_handler)( void *area )

)

{

  boolean                            found;

  POSIX_Interrupt_Handler_control   *the_intr;

  POSIX_Interrupt_Control           *the_vector;

  POSIX_API_Thread_Support_Control  *thread_support;

  Chain_Node                        *the_node;

  if ( !_ISR_Is_valid_user_handler( intr_handler ) )

    return EINVAL;

  _Thread_Disable_dispatch();

  /*

   *  Since interrupt handlers do not have a user visible id, there is

   *  no choice but to search the entire set of active interrupt handlers

   *  to find this one.

   */

  found = FALSE;

  the_vector = &_POSIX_Interrupt_Information[ intr ];

  the_node = _Chain_Head( &the_vector->Handlers );

  for ( ; !_Chain_Is_tail( &the_vector->Handlers, the_node ) ; ) {

    the_intr = (POSIX_Interrupt_Handler_control *) the_node;

    if ( the_intr->handler == intr_handler ) {

       found = TRUE;

       break;

    }

    the_node = the_node->next;

  }

  if ( !found ) {

    _Thread_Enable_dispatch();

    return EINVAL;

  }

  if ( !_Thread_Is_executing( the_intr->server ) ) {

    _Thread_Enable_dispatch();

    return EINVAL;  /* XXX should be ENOISR; */

  }

  /*

   *  OK now we have found the interrupt handler and can do some work.

   */

  _Chain_Extract( &the_intr->Object.Node );

  the_intr->is_active = FALSE;

  the_vector->number_installed -= 1;

  thread_support = _Thread_Executing->API_Extensions[ THREAD_API_POSIX ];

  thread_support->interrupts_installed--;

  /*

   *  It is unnecessary to flush the semaphore since the handler can only

   *  be "removed" by the thread which installed it.  Thus it cannot be

   *  blocked on the semaphore or it would not be executing this routine.

   */

  _Objects_Close( &_POSIX_Interrupt_Handlers_Information, &the_intr->Object );

  _POSIX_Interrupt_Free( the_intr );

  _Thread_Enable_dispatch();

  return 0;

}

/*PAGE

 *

 *  22.3.1 Associate a User-Written ISR with an Interrupt, P1003.4b/D8, p. 74

 */

int intr_lock(

  intr_t  intr

)

{

  POSIX_Interrupt_Control           *the_vector;

  _Thread_Disable_dispatch();

  the_vector = &_POSIX_Interrupt_Information[ intr ];

  the_vector->lock_count++;

  _Thread_Enable_dispatch();

  return 0;

}

/*PAGE

 *

 *  22.3.1 Associate a User-Written ISR with an Interrupt, P1003.4b/D8, p. 74

 */

int intr_unlock(

  intr_t  intr

)

{

  POSIX_Interrupt_Control           *the_vector;

  _Thread_Disable_dispatch();

  the_vector = &_POSIX_Interrupt_Information[ intr ];

  if ( !--the_vector->lock_count ) {

    while ( --the_vector->deferred_count ) {

      _POSIX_Interrupt_Handler( intr );

    }

  }

  _Thread_Enable_dispatch();

  return 0;

}

/*

 *  22.3.2 Await Interrupt Notification, P1003.4b/D8, p. 76

 */

int intr_timed_wait(

  int                     flags,

  const struct timespec  *timeout

)

{

  Watchdog_Interval                  ticks;

  POSIX_API_Thread_Support_Control  *thread_support;

  ticks = _POSIX_Timespec_to_interval( timeout );

  thread_support = _Thread_Executing->API_Extensions[ THREAD_API_POSIX ];

  _Thread_Disable_dispatch();

    _CORE_semaphore_Seize(

      &thread_support->Interrupt_Semaphore,

      0,             /* XXX does id=0 hurt in this case? */

      TRUE,

      ticks

    );

  _Thread_Enable_dispatch();

  return _Thread_Executing->Wait.return_code;  /* XXX should be POSIX */

}

/*PAGE

 *

 *  _POSIX_Interrupt_Handler

 *

 */

void _POSIX_Interrupt_Handler(

  ISR_Vector_number   vector

)

{

  POSIX_Interrupt_Handler_control   *the_intr;

  POSIX_Interrupt_Control           *the_vector;

  POSIX_API_Thread_Support_Control  *thread_support;

  Chain_Node                        *the_node;

  int                                status;

  the_vector = &_POSIX_Interrupt_Information[ vector ];

  the_node = _Chain_Head( &the_vector->Handlers );

  for ( ; !_Chain_Is_tail( &the_vector->Handlers, the_node ) ; ) {

    the_intr = (POSIX_Interrupt_Handler_control *) the_node;

    status = (*the_intr->handler)( (void *) the_intr->user_data_area );

    switch ( status ) {

      case INTR_HANDLED_NOTIFY:

        thread_support = _Thread_Executing->API_Extensions[ THREAD_API_POSIX ];

        _CORE_semaphore_Surrender(

          &thread_support->Interrupt_Semaphore,

          0,                         /* XXX is id=0 a problem */

        );

        return;

      case INTR_HANDLED_DO_NOT_NOTIFY:

        return;

      case INTR_NOT_HANDLED:

      default:                            /* this should not happen */

        break;

    }

    the_node = the_node->next;

  }

  /* XXX

   *

   *  This is an unhandled interrupt!!!

   */

}